求一个脚本？

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<style type="text/css">
<!--
#Layer1 {
position:absolute;
width:107px;
height:120px;
z-index:1;
background-color: #CCCCCC;
display:none;
top: 32px;
left: 11px;
}
#Layer2 {
position:absolute;
width:122px;
height:120px;
z-index:2;
left: 170px;
top: 32px;
background-color: #CCCCCC;
display:none;
}
#Layer3 {
position:absolute;
width:127px;
height:120px;
z-index:3;
left: 333px;
top: 32px;
background-color: #CCCCCC;
display:none;
}
-->
</style>
</head><body>
<div id="Layer1">
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
    <tr>
      <td>1</td>
    </tr>
    <tr>
      <td>2</td>
    </tr>
    <tr>
      <td>3</td>
    </tr>
    <tr>
      <td>4</td>
    </tr>
    <tr>
      <td>5</td>
    </tr>
    <tr>
      <td>6</td>
    </tr>
  </table>
</div>
<div id="Layer2">
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
    <tr>
      <td>1</td>
    </tr>
    <tr>
      <td>2</td>
    </tr>
    <tr>
      <td>3</td>
    </tr>
    <tr>
      <td>4</td>
    </tr>
    <tr>
      <td>5</td>
    </tr>
    <tr>
      <td>6</td>
    </tr>
  </table>
</div>
<div id="Layer3">
  <table width="100%" border="0" cellspacing="0" cellpadding="0">
    <tr>
      <td>1</td>
    </tr>
    <tr>
      <td>2</td>
    </tr>
    <tr>
      <td>3</td>
    </tr>
    <tr>
      <td>4</td>
    </tr>
    <tr>
      <td>5</td>
    </tr>
    <tr>
      <td>6</td>
    </tr>
  </table>
</div>
<table width="50%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td><a href="#" onmouseover="Layer1.style.display='block';" onmouseout="Layer1.style.display='none'">菜单一</a></td>
    <td><a href="#" onmouseover="Layer2.style.display='block'" onmouseout="Layer2.style.display='none'">菜单二</a></td>
    <td><a href="#" onmouseover="Layer3.style.display='block'" onmouseout="Layer3.style.display='none'">菜单三</a></td>
  </tr>
</table></body>
</html>